Semicarbazide hydrochloride → 3-Amino-2-carbamoyl-4-phenylpyrazole

Reaction equation

[CH:1]([CH:3]([C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1)[C:4]#[N:5])=O.Cl.[NH2:13][NH:14][C:15]([NH2:17])=[O:16].[OH-].[Na+]>CO.O>[NH2:5][C:4]1[N:14]([C:15](=[O:16])[NH2:17])[N:13]=[CH:1][C:3]=1[C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1

Participants

Procedure

The α-formylphenylacetonitrile obtained above is dissolved in methanol-water (1:1-10:1, 200 ml), and to the solution is added with stirring semicarbazide hydrochloride (9.95 g) under ice cooling. After taking off the ice bath, the mixture is reacted for 12 hours. The reaction mixture is neturalized with 5N sodium hydroxide solution. The mixture is stirred for 20 minutes, and the resulting precipitate is separated by filtration, washed with water and dried to give 3-amino-2-carbamoyl-4-phenylpyrazole (16.82 g). This product is used in the subsequent procedure without further purification.